This invention relates to the art of tips or nozzles in apparatus for dispensing liquids such as adhesives, and more particularly to a new and improved cleaning system for such nozzles or tips.
Due to the miniaturization increase in electronic technology, various viscous and non-viscous adhesives were developed to adhere component assemblies (i.e. circuit boards, connectors, chips). Positive displacement pumps and the like were designed to apply the electronic adhesives. Some pumps interface with programmable controllers enabling accurate, multi-positioning, and rapid dispensing of the adhesives. Positioning and dispensing accuracies are vital to this electronic technology.
Micro dispensing of the electronic adhesive has been accomplished by means of disposable, hypodermic needle, dispensing tips. An example of a dispensing tip is shown in U.S. Pat. No. 4,572,103 issued Feb. 25, 1986, the disclosure of which is hereby incorporated by reference. The dispensing tips fasten to the dispensing pump using a "Leur" thread lock. These tips are very precise which translates to high costs. Currently, all dispensing tips are very difficult to clean of the electronic adhesive during and between application processes. Thus, the tips are disposed of, adding to the cost of such electronic component assembly processes.
A quick change micro dispensing tip with disposable liner for dispensing liquid such as viscous and non-viscous adhesives in electronic component assembling is shown and described in pending U.S. patent application Ser. No. 09/360,972 filed Jul. 27, 1999 entitled "Quick Change Micro Dispensing Tip With Disposable Liner," the disclosure of which is hereby incorporated by reference.
The dispensing tips described hereinabove require ultra clean, non contaminated surfaces for adhesive passage. Due to the fact that while in production a single, micro dispensing tip may be utilized for different adhesives or a single adhesive may become a source for contamination, a rapid, positive, and user friendly method and apparatus for cleaning the dispensing tip is required.